Hydroxystearic Acid

What Is It?

Hydroxystearic Acid is a fatty acid. In cosmetics and personal care products, Hydroxystearic Acid is used in skin care preparations.

Why Is It Used?

Hydroxystearic Acid cleans skin and hair by helping water to mix with oil and dirt so that they can be rinsed away.

Scientific Facts

Hydroxystearic Acid is structurally similar to stearic acid and both are obtained from naturally-occurring fats and oils. One method of production of Hydroxystearic Acid involves the hydrogenation of castor oil.

Safety Information

The Food and Drug Administration (FDA) includes Hydroxystearic Acid on its list of indirect food additives for use as a component of paper and paperboard, and as a lubricant having incidental contact with food.

The safety of Hydroxystearic Acid has been assessed by the Cosmetic Ingredient Review (CIR) Expert Panel. The CIR Expert Panel reviewed the available scientific data and concluded that Hydroxystearic Acid was safe as a cosmetic ingredient in the present practices of use.

CIR Safety Review: The CIR Expert Panel reviewed reproduction and developmental toxicity and genotoxicity data that found no significant effects at exposures likely to exceed that seen from expected cosmetic use concentrations. The sarcomas produced by subcutaneous injection of Hydroxystearic Acid were considered to be a physical phenomenon unrelated to the specific material injected and not relevant to the use of this ingredient in cosmetics. Under semioccluded and occluded patch testing conditions, the CIR Expert Panel recognized irritation was found with antiperspirant prototype formulations. It is the experience of the CIR Expert Panel that such formulations under those exaggerated conditions do produce irritation, but are not generally irritating in actual use.

FDA: Link to Code of Federal Regulations for Hydroxystearic Acid

Hydroxystearic Acid may be used in cosmetics and personal care products marketed in Europe according to the general provisions of the Cosmetics Regulation of the European Union. Ingredients of animal origin must comply with European Union animal by-products regulations.

Link to the EU Cosmetic Regulation: 

More Scientific Information

Hydroxystearic Acid, also known as 12-Hydroxyoctadecanoic Acid, is a used as a surfactant – cleansing agent in cosmetic and personal care products. Cleansing agents, are used for skin and hair-cleaning purposes and as emulsifiers in cosmetics. In this function, surfactants wet body surfaces, emulsify or solubilize oils, and suspend soil.

It is characteristic (and expected by some consumers) that such agents should contribute foaming and lathering properties to cleansing products and bubble baths. The listing includes not only soaps but also fatty acids that yield soaps upon reaction with an alkali.


Find out more about the regulation of Food Additives by the Food and Drug Administration

Food Ingredients and Packaging: http://www.fda.gov/Food/IngredientsPackagingLabeling/default.htm

Food Contact Substances: http://www.fda.gov/Food/IngredientsPackagingLabeling/PackagingFCS/defaul…

Substances Generally Recognized As Safe (GRAS): http://www.fda.gov/Food/IngredientsPackagingLabeling/GRAS/default.htm

Search the Code of Federal Regulations http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm

EU Cosmetics Inventory http://ec.europa.eu/consumers/cosmetics/cosing/